uniform float uTime;
uniform vec3 uColor;
uniform float uMaxAlpha;
uniform float uMinAlpha;
uniform float uWholeAlpha;
varying vec2 vUv;

void main() {

    const float PI = 3.1415926;
    vec3 color = uColor.rgb;
    float maxAlpha = uMaxAlpha;
    float minAlpha = uMinAlpha;

    float alpha = mix(minAlpha, maxAlpha, (cos(vUv.x * PI + uTime) + 1.) * uWholeAlpha);

    gl_FragColor = vec4(uColor,alpha);

}